<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>计算器2</title>
  <style>
body {
    display: flex;
    flex-direction: column;
}
  hr {
      display: flex;
      height: 1px;
      width: 130px;
      margin: 2px 40px;
      background-color: black;
  }
  tr {
      width: 200px;
      display: flex;
      flex-wrap: wrap;

  }
  td {
      display: flex;
      flex-direction: column;
      justify-content: center;
      width: 40px;
      height: 40px;
      border-radius: 20px;
      background-color: gray;
      font-size: 16px;
      text-align: center;
  }

  </style>
</head>
<body>
<div>算式:</div><hr>
<div>结果:</div><hr>
<table>
<tr>
    <td>C</td>
    <td>CE</td>
    <td></td>
    <td></td>
    <td>1</td>
    <td>2</td>
    <td>3</td>
    <td>+</td>
    <td>4</td>
    <td>5</td>
    <td>6</td>
    <td>-</td>
    <td>7</td>
    <td>8</td>
    <td>9</td>
    <td>*</td>
    <td>/</td>
    <td>.</td>
    <td>0</td>
    <td>=</td>
</tr>
</table>
</body>
</html>
